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| author | Kaz Kylheku <kaz@kylheku.com> | 2014-03-05 01:31:46 -0800 |
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| committer | Kaz Kylheku <kaz@kylheku.com> | 2014-03-05 01:43:17 -0800 |
| commit | b6b7464882986fc24d7e3e6f37b694593d1097a1 (patch) | |
| tree | 023d4ae7cb67b099c882526f9952e089dde92dcc /txr.1 | |
| parent | 67ac7a217bdfd6e4a813cc6caa68a75fb754e28b (diff) | |
| download | txr-b6b7464882986fc24d7e3e6f37b694593d1097a1.tar.gz txr-b6b7464882986fc24d7e3e6f37b694593d1097a1.tar.bz2 txr-b6b7464882986fc24d7e3e6f37b694593d1097a1.zip | |
* stream.c (vformat): Fix broken parsing of parameteric width and
precision (i.e. given by *). The simplest way to do this is to add a
state vf_star which is similar to vf_digits, and reuses much of the
logic via a goto. Fixing forgotten --fmt (push back char) when moving
from vf_precision to vf_spec state due to unhandled character.
Also, allowing a leading zero before a precision given as *
so that computed precisions can be combined with zero padding.
* txr.1: Documented leading zero better so it is clear it
combines with *. Restructured documentation.
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 96 |
1 files changed, 58 insertions, 38 deletions
@@ -11237,24 +11237,56 @@ The <letter> is a single alphabetic character which determines the general action of the directive. The optional width and precision can be numeric digits, or special codes documented below. -The width specifier gives the width of the character field in which the object's -printed representation is placed. If the printed representation overflows the -field width, then the field width is ignored. The default field width is zero. -If the width specifier begins with the < (left angle bracket) character, then -the printing will be left-adjusted within this field. Otherwise it will be -right-adjusted by default. The width can be specified as decimal digits, or as -the character *. The * notation means that instead of digits, the value of the -next argument is consumed, and expected to be an integer which specifies the -width. If that integer value is negative, then the field will be left-adjusted. -(If that value is positive, but the < notation is present prior to the * -notation, the field will also be left-adjusted). - -The meaning of the precision specifier depends on the format directive. -Also, when the precision is not specified, the default behavior may be -different from any specific precision value. -If the precision has a leading zero, this has special semantics for numeric -conversions. The precision may also have a leading sign character, which -may be a plus or space. +.TP +width + +The width specifier consists of an optional < (left angle bracket) character, +followed by an optional width specification. + +If the < character is present, then the printing will be left-adjusted within +this field. Otherwise it will be right-adjusted by default. + +The width can be specified as a decimal integer, or as the character *. The * +notation means that instead of digits, the value of the next argument is +consumed, and expected to be an integer which specifies the width. If that +integer value is negative, then the field will be left-adjusted. +If the value is positive, but the < character is present in the width +specifier, then the field is left adjusted also. + +.TP +precision + +The precision specifier consists of an optional combination of the +special leading characters 0 (the "leading zero flag"), + (print a sign for +positive values") or space (print a space in place of a positive sign), +followed by a specification of the precision value, which is either a decimal +integer that does not begin with a zero digit, or the * character. + +The precision field's components have a meaning which depends on the type of +object printed and the conversion specifier. + +For integer arguments, the precision value specifies the minimum number of digits +to print. If the precision field has a leading zero flag, then the integer is +padded with zeros to the required number of digits, otherwise the number is +padded with spaces instead of zeros. If zero or space padding is present, and +a leading positive or negative sign must be printed, then it is placed before +leading zeros, or after leading spaces, as the case may be. + +For floating-point values, the meaning of the precision value depends on which +specific conversion specifier (f, e, a or s) is used. The details are +documented in the description of each of these, below. The leading zero flag is +ignored for floating-point values regardless of the conversion specifier. + +For integer or floating-point arguments, if the precision specifier has a + sign +among the special characters, then a + sign is printed for positive numbers. If +the precision specifier has a leading space instead of a + sign, then the + +sign is rendered as a space for positive numbers. If there is no leading space +or +, then a sign character is omitted for positive numbers. Negative +numbers are unconditionally prefixed with a - sign. + +For all other objects, the precision specifies the maximum number of characters +to print. The object's printed representation is crudely truncated at that +number of characters. .TP Format directives: @@ -11267,28 +11299,16 @@ Prints any object in an aesthetic way, as if by the pprint function. The aesthetic notation violates read-print consistency: this notation is not necessarily readable if it is implanted in TXR source code. The field width specifier is honored, including the left-right adjustment -semantics. The precision field has a meaning as follows. For integer objects, -the precision specifies the minimum number of digits to print. (A leading -sign does not count as a digit). If the precision field has a leading zero, -then the number is padded with zeros to the required number of digits, -otherwise the number is padded with spaces instead of zeros. If zero or space -padding is present, and a leading positive or negative sign must be printed, -then it is placed before leading zeros, or after leading spaces, as the case -may be. If the precision specifier has a leading + sign, then a + sign is -printed for positive numbers. If the precision specifier has a leading space -instead of a + sign, then the + sign is rendered as a space for positive -numbers. If there is no leading space or +, then a sign character is omitted -for positive numbers. For floating point values, the precision specifies +semantics. + +When this specifier is used for floating-point values, the precision specifies the maximum number of total significant figures, which do not include any digits in the exponent, if one is printed. Numbers are printed in exponential -notation if their magnitude is small, or else if their exponent exceeds -their precision. (If the precision is not specified, then it defaults to -the system-dependent number of digits in a floating point value, derived -from the C language DBL_DIG constant.) Floating point values which are -integers are printed without a trailing .0 (point zero). For all other objects, -the precision specifies the maximum number of characters to print. -The object's printed representation is crudely truncated at that number -of characters. +notation if their magnitude is small, or else if their exponent exceeds their +precision. (If the precision is not specified, then it defaults to the +system-dependent number of digits in a floating point value, derived from the C +language DBL_DIG constant.) Floating point values which are integers are +printed without a trailing .0 (point zero). .IP s Prints any object in a standard way, as if by the print function. Objects for |